Collision detection is the determination of whether or not two or more entities make contact with each other during gameplay.

learn more… | top users | synonyms (2)

2
votes
1answer
894 views

Inaccurate 3D model collision using XNA

I am creating a classic game in 3D that deals with asteriods and you have to shoot them and avoid being hit from them. I can generate the asteroids just fine and the ship can shoot bullets just fine. ...
3
votes
3answers
399 views

Collision filtering techniques

I was wondering what efficient techniques are out there for mapping collision filtering between various bodies, sub-bodies, and so forth. I'm working on a physics engine and I need ways for a user to ...
1
vote
2answers
756 views

Axis-Aligned Bounding Boxes vs Bounding Ellipse

Why is it that most, if not all collision detection algorithms today require each body to have an AABB for the use in the broad phase only? It seems to me like simply placing a circle at the body's ...
10
votes
2answers
2k views

Continuous Physics Engine's Collision Detection Techniques

I'm working on a purely continuous physics engine, and I need to choose algorithms for broad and narrow phase collision detection. "Purely continuous" means I never do intersection tests, but instead ...
2
votes
1answer
752 views

Collision with half of a semi-circle

I am trying to port a game I made using Flash/AS3, to the Windows Phone using C#/XNA 4.0. You can see it here: http://goo.gl/gzFiE In the flash version I used a pixel-perfect collision between ...
0
votes
1answer
391 views

Almost working 2D Collisions

I'm terribly sorry I'm asking this question YET AGAIN, but I can almost guarantee that this will be the last time I'll have to ask. I'm currently on the verge of FINALLY getting these collisions to ...
3
votes
1answer
1k views

Collision Detection on floor tiles Isometric game

I am having a very hard to time figuring out a bug in my code. It should have taken me 20 minutes but instead I've been working on it for over 12 hours. I am writing a isometric tile based game where ...
0
votes
2answers
460 views

Collisions not working as intended

I'm making a game, it's a terraria-like game, with 20x20 blocks, and you can place and remove those blocks. Now, I am trying to write collisions, but it isn't working as I want, the collision ...
3
votes
1answer
1k views

Movement and Collision with AABB

I'm having a little difficulty figuring out the following scenarios. In scenario A, the moving entity has fallen to (and slightly into the floor). The current position represents the projected ...
2
votes
3answers
1k views

Coarse Collision Detection in highly dynamic environment

I'm currently working a 3D space game with A LOT of dynamic objects that are all moving (there is pretty much no static environment). I have the collision detection and resolution working just fine, ...
9
votes
1answer
474 views

Deforming surfaces

I try to accomplish an deforming physic behaviour for levelsurfaces, but don't get an idea how to start with the implemenation so far. Regardless of the shape from the surface (planes, cubes, ...
2
votes
1answer
1k views

How to resolve concurrent ramp collisions in 2d platformer?

A bit about the physics engine: Bodies are all rectangles. Bodies are sorted at the beginning of every update loop based on the body-in-motion's horizontal and vertical velocity (to avoid sticky ...
1
vote
1answer
340 views

What exactly is the difference between separation and obstacle avoidance

I've been reading some literature that explains both separation and obstacle avoidance. On first sight, they both seem very similar in what they are supposed to do: keeping objects apart form each ...
3
votes
2answers
331 views

How to make it so units don't stack up in one location? [duplicate]

Possible Duplicate: Is there a simple way to stop enemies standing in the same spot? So I'm making a game in AS3, it's a strategy DotA-like game (for flash game equivalent, there's UDE) so ...
1
vote
1answer
521 views

What do I need to do to my slope collision detection to prevent the player from passing through my collision?

I've recently implemented slope collision detection for my project. The issue I'm having is that the character occasionally passes through the line. This usually occurs when the characters ...
2
votes
1answer
700 views

Can Bullet Physics (or another 3d physics engine) use callbacks in my engine to check static geometry?

I'm wondering if it's possible to use or hack Bullet 3d Physics (or another free 3D physics engine) so that I don't need to "import" my static geometry into Bullet - instead I want to do it the other ...
2
votes
1answer
2k views

Collision detection between a sprite and rectangle in canvas

I'm building a Javascript + canvas game which is essentially a platformer. I have the player all set up and he's running, jumping and falling, but I'm having trouble with the collision detection ...
2
votes
2answers
567 views

3d Collision detection help xna?

I was hoping if you could help me out here. I'm developing a 3d table tennis game, and got the collision detection working perfectly when the ball hits the racket. However, now I would like the ball ...
6
votes
1answer
2k views

Minecraft-style player-gound collision detection

The title pretty much says it all... (Minecraft is a game consisting of evenly-spaced cubes for terrain, like voxels) Note: I am using C# XNA. I am pretty sure AABB is the way to go, yet I don't know ...
9
votes
3answers
635 views

How to separate colliding objects without creating more collisions

Suppose I use a simple discrete collision detection system where I move all objects then check for collisions. I want any colliding objects to be separated (of course) and assigned appropriate ...
2
votes
5answers
1k views

How do I set up moving platforms in a 2D side scroller to interact with the player properly?

Edit: I changed the way that gravity was applied so that it is applied even when a player is standing on a block, so instead of the game outputting that you are stepping on a tile as true and false ...
1
vote
3answers
2k views

How can I determine the velocity after impact of a 2D ball collision?

Consider two balls moving towards each other. Each has a given mass and velocity. Assuming the balls collide, how can you determine what direction the balls will take afterwards? (taking into ...
7
votes
2answers
3k views

How do I handle collision detection so fast objects are not allowed to pass through walls?

I'm creating a 2d sidescrolling shooter, and I'm having a little trouble with collision detection for the bullets. Everything including the bullets are objects with their own polygons / update ...
0
votes
1answer
157 views

How can I handle transferring a character from one collision surface to another?

I've been trying to modify some slope code from an example I've found but I've come across an issue the way the method is designed it attaches the current slope and then based off that slope ...
29
votes
7answers
23k views

most efficient AABB vs Ray collision algorithms

Is there a known 'most efficient' algorithm for AABB vs Ray collision detection? I recently stumbled accross Arvo's AABB vs Sphere collision algorithm, and I am wondering if there is a similarly ...
1
vote
1answer
1k views

Line segment / circle intersection - X value seems wrong?

Major Edit I'm making a Breakout clone, and having difficulty with collision detection between a circle and line segment. Apologies, my earlier question was a result of frustration and no sleep :) ...
9
votes
1answer
4k views

Circle-Line Collision Detection Problem

I am currently developing a breakout clone and I have hit a roadblock in getting collision detection between a ball (circle) and a brick (convex polygon) working correctly. I am using a Circle-Line ...
3
votes
1answer
2k views

2D circle / rectangle collision detection issue - brief overlap

I'm currently trying to build a Breakout clone as a first step into game development. I'm using the following collision detection code (adapted from ...
5
votes
4answers
7k views

2D Platformer Collisions

I've basically asked this question before, and I know it's been asked probably a billion times, but I still can't seem to do it. All I want to know is how I should go about doing basic 4-way, ...
1
vote
1answer
514 views

Updating XNA BoundingSphere - sphere moves in opposite Y direction?

In my players update method I calc the new world matrix then I update a boudingsphere by: MyBoundingSphere = MyBoundingSphere.Transform(World); However when the the model's World has moved ...
3
votes
3answers
3k views

How can I implement fast, accurate 2D collision detection?

I'm well aware of how to detect if two or more 2D objects collide but I'm interested in how to decide whether to check for a collision. In previous projects, I just had every object check against ...
4
votes
1answer
2k views

How can I detect collision between a circle and a rectangle?

i'm trying to make a clone of brick breaker, one problem that i am running in to is to do with collision. i know how to detect if a collision has happened but i do not know how to check what side of ...
5
votes
2answers
521 views

How to detect collision with non-rectangular objects in 2D games?

Detecting collision with rectangular objects is quite easy. I am able to write simple tile based games. Now I want to learn to write non-tile based games in which objects may not be rectangular, for ...
3
votes
3answers
977 views

XNA: Perform Collision Detection Against 3D Scene Geometry

How would one perform collision detection between a simple scene like the one below and a simple object like a sphere? I assume the best solution would involve convex hulls in some way but I have no ...
1
vote
4answers
2k views

Basic 2D game collision

I've been trying to program a game for the past while and I can't ever figure out one thing: collision detection. I can get up+down and left+right to work, but when I put them together, they interfere ...
20
votes
4answers
4k views

How to deal with corner collisions in 2D?

I'm writing a top down 2d XNA game. Since its my first I'm trying to write the physics and collision stuff myself to learn it. Whenever my player sprite character attempts to move into a position ...
2
votes
3answers
4k views

Clean way to detect collision of object with box2d

I have been looking into box2d (in java with libgdx) lately and have been trying to create my own custom bounce effect (I increase the Restitution after the first bounce) To do this as a test I ...
0
votes
1answer
913 views

How to find which side of a collider has been hit from hit.normal?

In Unity3d, i can get the normal of the surface with which the collider collides using hit.normal, but is there a way to find which side has been hit what is provided bu Unity3d? One solution is to ...
5
votes
1answer
4k views

How can I set up a Pong-style game using the physics system in Unity?

I've just been using Unity and chose to learn it by making a Pong game which sounded simple enough as a "hello world" type of game. My goal was to try and encompass enough of the built in engine ...
6
votes
1answer
956 views

XNA Platformer Collision: PerPixel vs Rectangle

I'm writing a platformer engine with XNA and was wondering what method for handling collisions I should use. Would I be seeing some performance issues if I were to try and have PerPixel collisions? ...
7
votes
3answers
769 views

Polygon editor to draw collision data over image

I need an editor to plot a polygon over the texture for of a ship in my game. It would look like this.. Where the red is the collision outline and the image is the texture. I want to store the ...
16
votes
1answer
907 views

How to resolve collisions of compound shapes using SAT?

SAT is a decent way to determine collisions between arbitrary convex polygons. You'll even get the vector that is needed to resolve a collision. To resolve collisions between complex (non-convex) ...
3
votes
1answer
238 views

Collision Managers and bitmaps

I am rewriting a game I made to use a (custom) collision manager that uses the minimum displacement method. As of now, my simple manager can only recognize and act on a couple of shapes - Circles and ...
1
vote
1answer
1k views

Sphere collision response

I have simple mechanism for testing of two balls colliding: private static boolean isColliding(float firstBallX, float firstBallY, double firstBallRadius, float secondBallX, float secondBallY, double ...
-1
votes
1answer
988 views

Collision detection problem

I am a novice in android. It's my first game, so I am trying to make a frogger clone. I am getting a problem in collision detection. In logcat, even though the frog is not moving and not colliding ...
12
votes
3answers
4k views

2D game collision response: SAT & minimum displacement along a given axis?

I'm trying to implement a collision system in a 2D game I'm making. The separating axis theorem (as described by metanet's collision tutorial) seems like an efficient and robust way of handling ...
1
vote
1answer
2k views

Setting up collision using a tilemap and cocos2d

I'm building my first platformer using cocos2d and a tilemap. I'm having trouble coming up with a decent way of determining if the character is colliding with an object. More specifically, in which ...
1
vote
1answer
1k views

What is wrong with my collision detection code?

I want to check collision detection between two bitmaps but I am not getting how to do it. I read several queries and tutorials but didnt get properly. I want to check by their width and height. I ...
6
votes
2answers
470 views

Is it possible to have concurrent collision detection where every entity acts at exactly the same time?

There are many algorithms that can be used for collision detection. In many cases we check for an overlap in coordinates of an entity. If we make a triangle a,b and c. We have 2 entities at a and b ...
8
votes
1answer
2k views

Am I going to regret using a color based collision detection system?

I'm just getting started build my first game with XNA (I'm experienced with C# but not games). I'm building a pretty simple top down 2d shooter. I read this tutorial on using a color based collision ...